The invention relates generally to digital cameras and more particularly to a digital camera with printing capability.
A digital camera captures an image of a particular subject using an imaging system that includes an optical lens and a photosensor array, such as a charged coupled device (CCD). The imaging system xe2x80x9ccapturesxe2x80x9d a set, or frame, of digital image data that represents a particular subject at the time that the frame is captured. Each frame of digital image data is stored in a memory of the digital camera for subsequent viewing on a display or downloading to a computer system for editing and printing.
In order to print the captured image, a host computer is typically utilized. The frame of digital image data is transferred from the digital camera to the host computer. Once the frame of digital image data has been received, the host computer can display the captured image represented by the frame of digital image data on a monitor using photo-manipulation software. The host computer can then print the captured image to any standard printer, or a special photography printer, such as the Hewlett Packard (HP) PhotoSmart Photo Printer, that is attached to the host computer. However, this typical approach requires access to a host computer and the sophistication to utilize the photo-manipulation software.
An alternative photo-printing approach is to employ a dedicated printer that is directly connected to a digital camera. U.S. Pat. No. 4,074,324 to Barrett describes an instant electronic camera that is directly connected to an external mechanical scanning printer. If digital image data is captured at a location distant from the printer, the camera must be brought to the location of the printer in order to print the image data.
Similarly, U.S. Pat. No. 4,827,347 to Bell describes an electronic camera that is directly connected to a database/picture printer. Unlike the instant electronic camera of Barrett, the electronic camera of Bell has an array of display windows on the opposite side of a lens assembly for viewing stored frames of digital image data prior to printing or downloading.
Still another approach to printing the frame of digital image data is to have a printer that is incorporated into the digital camera or is attached physically to a camera housing of the digital camera. U.S. Pat. No. 4,937,676 to Finelli et al. (hereinafter Finelli) describes an electronic camera system with a detachable printer. The detachable printer of Finelli utilizes a self-developing film that is exposed according to the digital image data. Thus, photo-imageable film is required to print an image. Moreover, the system described in Finelli offers little flexibility with respect to photograph manipulation (e.g., varying the size of a photo-print).
U.S. Pat. No. 5,493,409 to Maeda. et al. (hereinafter Maeda) describes a still video camera having a printer. In one embodiment, a printing mechanism is incorporated into a still video camera. In this embodiment, a television set is utilized to view the electronic images. In another embodiment, a printing mechanism is a detachable printer unit. In both embodiments, the captured image can only be printed in one size.
While the known devices for capturing and printing images operate well for their intended purpose, an efficient and inexpensive camera for capturing and printing frames of digital image data in various sizes is desired. What is needed is a compact digital camera with printing capability that could print the frame of digital image data onto any of a variety of types of print media and preferably within a range of different sizes.
A method and apparatus for capturing and printing an image includes utilizing a tracking mechanism to allow an operator to print the captured image onto a selected print medium by moving the apparatus in a free-hand manner across a print medium. The changing location of the apparatus is monitored in real time using navigation information generated by the tracking mechanism. The apparatus is a print-capable digital camera having conventional circuitry for capturing an image, but also having a printing capability that is controlled by the navigation information generated by the tracking mechanism.
In the preferred embodiment, the tracking mechanism is at least one trackball that extends beyond an external surface of the digital camera. Also in the preferred embodiment, the printing capability is achieved by locating a printhead of an inkjet cartridge at the external surface. Rotation of the trackball or trackballs is monitored in real time to generate the navigation information that allows determination of the position of the inkjet printhead relative to a start position for the printing process. While inkjet printing is preferred, other printing devices may be utilized.
In operation, a frame of digital image data is captured and stored using conventional techniques. During a printing process, the frame of image data is converted to print data compatible with the printing device. The print data is dynamically arranged in segments in response to receiving the navigation information. For example, if two trackball assemblies generate navigation information, the location of the printhead may be determined within X, Y coordinates, and segments of the print data may be transmitted to the printhead accordingly. As long as the trackball assemblies are in constant contact with the surface on which the image is printed, the digital camera may retrace any missed areas in order to complete the print image. Preferably, the digital camera prints only the missed area when there is an overlap, but duplicate printing may be utilized.
Rather than trackball assemblies, the navigation information may be generated by an optical imaging structure. For example, during a printing process, images of the surface on which the print material is deposited may be repeatedly captured and compared to each other to determine the direction of movement by the digital camera. Successive determinations are used to arrange the print data for forming the image of interest on a print medium, such as a sheet of paper.
The digital camera may include an optical lens for optically focusing an image onto an array of elements that generate output signals indicative of light received at a selected time. Collectively, the signals form a frame of image data. In the preferred embodiment, the imaging array is fabricated as part of an application specific integrated circuit (ASIC) that also includes analog-to-digital circuitry, timing control circuitry, memory and digital signal processing circuitry. Also included on the ASIC is a printer driver, which is typically implemented in computer software. The dynamic arrangement of segments of print data may be implemented at the driver level, or at a level above or below the driver level. That is, the printer driver may direct print data in an arrangement of segments responsive to the reception of navigation information. Alternatively, the dynamic arrangement of segments may be implemented prior to the printer driver by arranging the image information that is conducted to the printer driver. As the third alternative, the print data from the driver may be temporarily stored in a buffer, and the dynamic arrangement may be the result of extracting print data from the buffer in an arrangement dictated by the navigation information.
Preferably, the printer driver enables a user to select the size of the image that is printed. The digital camera includes an interface that allows magnification and demagnification of the image to be printed.